Dry Eye Disease May Decrease Reliability of Glaucoma Metrics

When using gaze tracking in a visual field test, the symptom severity of dry eye disease may influence the tracking failure frequency (TFF) threshold, according to results of a study published in the Journal of Glaucoma.

Patients (N=494) with glaucoma, suspected glaucoma, and ocular hypertension who responded to the five-item Dry Eye Questionnaire (DEQ-5) and underwent visual field testing at the Veterans Administration Medical Center San Diego between 2018 and 2019 were included in this study. Gaze tracking metrics were evaluated on the basis of dry eye symptoms.

Patients were aged mean 66.3±11.3 years, 6.1% were women, 65.4% were not taking any glaucoma medication, and 24.7% used artificial tears.

During DEQ-5 assessment, 37.4% had minimal, 40.1% moderate, and 22.5% severe dry eye symptoms. Use of artificial tears increased with dry eye severity (P <.001).

At the visual field evaluation, 84.7% of the 988 eyes had minimal, 9.9% moderate, and 5.4% severe visual field loss.

Using previously published binarized limits, 33% of eyes were rejected for high fixation losses and 3.5% and 3.1% were rejected for high false positives and negatives, respectively.

The gaze tracking metrics were defined using the 95th percentile of this patient population. Rejection rates did not differ between left and right eyes for gaze deviation between 1˚ to 2° (M1), 3˚ to 5° M3, or ≥6° (M6). For TFF, left eyes were more likely to be rejected than right eyes (6.9% vs 4.4%; P =.012).

Similar to left and right eyes, the rate of rejection due to fixation losses, false positives, false negatives, M1, M3, and M6 did not differ on the basis of dry eye symptom severity. However, TFF in 1 eye (4.9% vs 8.6% vs 13.5%) and both eyes (0.0% vs 1.0% vs 2.7%) increased with dry eye symptom severity (P =.015).

This study was limited by recruiting an overwhelmingly male population and these results may not be generalizable to other populations.

These data indicated that TFF associated with dry eye symptom severity during visual field testing. 

The study authors also note that TFF differed for left eyes, or the second eye to be tested. Both factors should be taken into consideration when interpreting TFF as a marker of visual field loss.

Reference

Camp AS, Long CP, Galor A, Yamane M, Proudfoot JA, Weinreb RN. Dry Eye symptom severity and visual field reliability metrics. J Glaucoma. 2022;31(5):305-309. doi:10.1097/IJG.0000000000002017